For three months, Anders Agger follows life at Sikringen in Slagelse. A place that, from the outside, looks like a high-security prison but is, on the inside, a psychiatric hospital treating 30 of the country's most severely ill psychiatric patients. The patients have committed violent acts in the past and remain dangerous in the present. That is why the security around them is extreme.

Over tre måneder følger Anders Agger livet på Sikringen i Slagelse. Et sted, som udefra ligner et topsikret fængsel, men indefra er et psykiatrisk hospital, der behandler 30 af landets sygeste psykiatriske patienter. Patienterne har gjort voldsomme ting i deres fortid, og er fortsat farlige for deres nutid. Derfor er sikkerheden omkring dem ekstrem.